1. The easiest way I find to upload and Image is to first upload it to a website called
. This makes it easier to add your file.
2. To upload you image to imgur, you want to click the button that follows where you are uploading form, If it is a picture from your Files then click the button labeled 'Computer' which will open your file browser and it is as simple as locating the image and clicking open.
3. The image will load into a box in your web browser. After that you will need to click the button labelled 'Start Upload'.
4. After that your image will appear with a selection of options to the right of the page. The one you want is called 'BBCode (message boards & forums)'
5. After you have got the contents of the box copied, you can simply paste it into your post on this website.
I always use the friendly image link button towards the right-hand end of the toolbar (above the woohoo smiley?) at step 5 rather than manually add the IMG tags. This may well be what Warren is thinking of, too.
I use my own web-site to host the files but I realise that's not for everyone.